Browse Prior Art Database

Input/Output Controller

IP.com Disclosure Number: IPCOM000077647D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Reed, JW: AUTHOR

Abstract

Control of input/output devices is accomplished by a control unit which arranges all data and central lines into a register storage structure. The registers can be accessed and processed just like other operand registers in the unit.

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Input/Output Controller

Control of input/output devices is accomplished by a control unit which arranges all data and central lines into a register storage structure. The registers can be accessed and processed just like other operand registers in the unit.

The instructions which operate to control and sequence the external I/O device are contained in the control storage unit 1. The instruction at the address specified by address register 2 is fetched and held in output register 3. While a discrete output register 3 is shown, this register may be replaced by the data output lines if the storage unit 1 is of the type which provides static data signals as long as the signals from the address register 2 are present.

The instructions fetched from control storage unit 1 serve to address the local and external registers in buffer storage unit 5 by address decode 6. A portion of the instruction in output register 3 is gated to address decode 6 to select the appropriate register in buffer 5. Control for writing into buffer 5 from arithmetic logic unit (ALU) 7 is provided by the Write Line 10.

The input lines 15 associated with buffer storage unit 5 come from ALU 7. A similar set of input lines 16 come from the external device. By fetching the appropriate instruction from control storage unit 1, data from the ALU or an external device can be gated onto the buffer storage output lines 17. The signals to and from an external device represent data, control information or sta...